Am J Psychiatry 1997; 154:378-383
Copyright © 1997 by American Psychiatric Association
Abnormal brain hemodynamic responses during passive orthostatic challenge in panic disorder
C Faravelli, M Marinoni, R Spiti, A Ginanneschi, A Serena, C Fabbri, C Di Matteo, M Del Mastio and D Inzitari
Department of Neurology and Psychiatry, Florence University Medical School, Italy.
OBJECTIVE: Autonomic dysregulation and cerebral blood flow (CBF)
abnormalities have been reported in patients with anxiety disorders and,
more recently, in panic disorder. Variations in the middle cerebral artery
velocity (measured by transcranial Doppler technique), heart rate, and
blood pressure during a tilting-table test were used as nonanxiogenic
procedures to explore these abnormalities. METHOD: Mean flow velocity in
the right middle cerebral artery, heart rate, and blood pressure were
monitored at rest and during a 70 degrees tilting- table test. Three groups
of patients were studied: 11 patients (eight women and three men; mean age
= 31.1 years, SD = 8.0) with a diagnosis of panic disorder within 6 months
of the onset of the disorder, nine asymptomatic patients (two men and seven
women; mean age = 35.0, SD = 6.3) with a previous diagnosis of panic
disorder who were in full remission of symptoms and had been drug free for
at least 6 months, and 10 normal comparison subjects (two men and eight
women; mean age = 31.1, SD = 5.2). RESULTS: Both patients with acute panic
disorder and patients with remitted panic disorder showed a significant
percent reduction of right middle cerebral artery mean flow velocity
compared with normal subjects following tilting to the upright position. No
significant differences were observed for blood pressure and heart rate.
CONCLUSIONS: Patients with panic disorder, both during the acute phase of
the illness and after clinical recovery, show an exaggerated drop in CBF
during tilting. Since these findings are similar, although attenuated in
intensity, to those which are observed in dysautonomic illnesses, one
possible interpretation is that of panic disorder as a subclinical form of
autonomic dysreactivity.
